This work to which God calls husbands is far from easy (in fact it's very challenging, even for men considered "spiritually mature"), but it is not really theologically complex.
If you have ever had a relationship where you knew you weren't always being treated the way that you should or been in a relationship in which you couldn't share your faith with your partner, it's okay.
My own wife has made me a better man and a better Christian in too many ways for me to count.
That is perfectly in line with the Bible's notion of a wife as "helpmate" (see Genesis 2).
I would not normally encourage a situation in which a wife is consistently discipling her husband in Christian basics, and as I wrote above, the husband will necessarily set the basic spiritual tone for the home (for better or worse).
But challenge, encouragement, instruction in something the wife knows more about — all this can and should happen in a home where the husband is still the overall spiritual leader. As your question implies, there is a difference between theological knowledge and spiritual maturity.